The UK’s National Crime Agency said it arrested four young people on Thursday in connection with the disruptive cyberattacks that hit Marks & Spencer, the Co-op and Harrods earlier this year. A 20-year-old woman was detained in Staffordshire, while three males aged 17 to 19 were held in London and the West Midlands. Investigators seized electronic devices during dawn raids and are questioning the suspects on suspicion of Computer Misuse Act offences, blackmail, money laundering and participation in an organised crime group. The arrests follow a months-long investigation into a series of hacks that began in April and have been linked by security researchers to the so-called Scattered Spider group of English-speaking hackers. Paul Foster, head of the NCA’s National Cyber Crime Unit, called the detentions “a significant step” in efforts to bring those responsible to justice, adding that the probe remains one of the agency’s top priorities. M&S has estimated the cyberattack will cut its profits by about £300 million and temporarily wiped roughly £1 billion from its market value. The retailer warned some of its IT systems may not be fully restored until October or November. The Co-op experienced weeks of empty shelves, while Harrods said it disconnected parts of its network to contain the breach. Authorities said the investigation continues alongside domestic and overseas partners.